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    <title>Document</title>
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  <body>
    <script>
      // 借用父构造函数继承属性
      // 1. 父构造函数
      function Father(uname, age) {
        // this 指向父构造函数的对象实例
        this.uname = uname
        this.age = age
      }
      // 2 .子构造函数
      function Son(uname, age, score) {
        // this 指向子构造函数的对象实例
        Father.call(this, uname, age)
        this.score = score
      }
      var son = new Son("敌法师", 18, 100)
      console.log(son)
    </script>
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